A novel timing estimation method for OFDM systems over multipath fading channels

In this paper, a novel symbol timing estimator is presented for Orthogonal Frequency Division Multiplexing (OFDM) systems in multipath Rayleigh fading channels. The estimator exploits the redundancy of cyclic prefix (CP) to achieve coarse timing synchronization as conventional methods, but in order to mitigate the effects of the multipath, the length of the computation correlation window is adjusted according to the maximum time delay which is estimated by multipath information estimator in previous frame. In addition, the, further fine synchronization is accomplished according to the multipath information estimated in current frame. Simulations demonstrate that the proposed symbol timing estimator performs a significant improvement compared to the conventional methods, which indicate its high suitability for the OFDM symbol synchronization in multipath fading channel environment.